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Ethanol rises as a fossil fuel alternative

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There's an adage that one hears occasionally in some tech circles. It says that "when it's steam engine time, people will invent steam engines."
Korky Koroluk
Korky Koroluk

Construction Corner | Korky Koroluk

There's an adage that one hears occasionally in some tech circles. It says that "when it's steam engine time, people will invent steam engines."

History tells us that a mathematician and engineer named Hero of Alexandria invented a rudimentary steam engine called an aeolipile in Roman Egypt in the 1st century. But, it was another 1,700 years or so before someone would invent the steam engine that powered the Industrial Revolution.

That new steam engine was made possible by better materials to make it from, plenty of coal for fuel, and, most important, a growing industrial demand for an alternative source of power.

It was, in other words, “steam engine time,” and in 1781, James Watt patented the first practical, operating steam engine.

Now, it’s time for another big technological leap, a paradigm shift.

The search for an environmentally friendly fuel to power our society has been going on for years now.

Petroleum-based gasoline and diesel spew too much carbon dioxide into the atmosphere, so we’ve been experimenting with alternatives. That’s why, in most provinces and states, ethanol makes up a modest percentage of every litre of fuel you buy at the pumps. That’s why the diesel delivered to your jobsite often contains a measure of biodiesel, usually derived from vegetable oil rather than petroleum.

Ethanol for blending with gasoline, is, in North America, most often derived from corn, but that was a bad choice.

Planting, harvesting and transporting the corn to market uses so much fossil fuel that the reduction in greenhouse gas emissions achieved with ethanol is negligible.

The increased demand for corn pushes the price up, and fertile cropland is used to grow corn for ethanol, instead of food. Still, when Steven Chu, a Nobel Prize-winning physicist, who later became energy secretary in the U.S. government, began musing about a glucose-based economy, many people rolled their eyes at how impractical scientists could sometimes be.

We’ve long known that you can make ethanol from cellulose, the indigestible fibre found in wood and the grasses that flourish on scrub land no one farms.

Until now, there was no way to produce this cellulosic ethanol and bring it to market at a competitive price.

But the U.S. National Renewable Energy Laboratory (NREL) has come up with not one, but two ways to produce cellulosic ethanol at a reasonable price.

The challenge had been thrown out by the federal energy department in 2006: produce cellulosic ethanol from non-food plant sources for $2.15 a gallon.

The NREL used two pathways to reach the objective.

One, a thermochemical process, involves gasifying biomass like wood chips, corn stover and other agricultural waste, to obtain “syngas,” which is made up of hydrogen and carbon monoxide, then using a catalyst to convert the syngas to ethanol.

The other method the lab followed was a biochemical path, which involved the degradation of cellulose into simple sugars by pre-treating the cellulose, then using enzymes to digest it. Micro-organisms then ferment the sugars derived to obtain ethanol and other alcohols.

The chemistry is complex, which explains why it took the lab more than six years to meet the challenge, but they met it.

The thermochemical method gave them ethanol that could be sold at $2.05 a gallon. The biochemical process leading from cellulose to simple sugars to ethanol, came in at $2.15 a gallon. Those prices are competitive with corn-based ethanol, but without the penalties that corn brings to the process. The work also leads to something else.

Chu mused about a glucose-based economy, and glucose is one of the simple sugars the NREL’s process produces.

That glucose could be piped around the country as easily as we pipe oil.

When it was time, we invented steam engines. Now it’s time we invented a viable alternative to fossil fuels.

Korky Koroluk is a regular freelance contributor to the Journal of Commerce. Send comments or questions to editor@journalofcommerce.com.

by Journal Of Commerce

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